Hi Iurii, Thanks so much for your help. My code is working now, I think there was an error somewhere in
Modules/set_hubbard_l.f90 Modules/set_hubbard_n.f90 PW/src/tabd.f90 As after redownloading / compiling with my new Hubbard channels everything seemed to worked fine. Thanks also for pointing me to the example with hubbard_back, as this also helped a lot too. One question, you said: 'This modification must be done for both DFT+U and DFT+U+V machineries' You are talking about editing 'set_hubbard_l' and 'set_hubbard_l_back' to my desired values? and this is done in 'Modules/set_hubbard_l.f90' Cheers Will On Tue, Aug 18, 2020 at 8:57 PM Timrov Iurii <[email protected]> wrote: > > Note that by default the second Hubbard channel per atom is of the "s > character". > > > Sorry, this is true for most elements. But just for a few elements the > second Hubbard channel is not of the s character. One should always check " > set_hubbard_l_back". > > > In the (near) future we would like to make it possible to specify the > Hubbard channels (i.e. orbitals to which the Hubbard correction is applied) > from the input, and not to have it hard-coded in set_hubbard_l and > set_hubbard_l_back. > > > Greetings, > > Iurii > > > -- > Dr. Iurii TIMROV > Postdoctoral Researcher > STI - IMX - THEOS and NCCR - MARVEL > Swiss Federal Institute of Technology Lausanne (EPFL) > CH-1015 Lausanne, Switzerland > +41 21 69 34 881 > http://people.epfl.ch/265334 > ------------------------------ > *From:* users <[email protected]> on behalf of > Timrov Iurii <[email protected]> > *Sent:* Tuesday, August 18, 2020 10:50:28 AM > *To:* [email protected] > *Subject:* Re: [QE-users] On-site Hubbard U for background orbitals > > > Dear Will, > > > The implementation of the multi-channel DFT+U and DFT+U+V codes is in the > experimental stage (please use it with caution), we are still working on > it to make it more user-friendly and robust. This is why there is no much > documentation about it yet. > > > In principle, yes you can use the DFT+U+V machinery to do what you want: > to apply two different U values to 4f and 5d states of Gd and set V to > zero. But actually there is a multi-channel implementation also in the > DFT+U machinery, but this was not advertised yet for the reasons > mentioned above. But you can see some examples in q-e-6.6/ > test-suite/pw_lda+U (in you case you should check " > lda+U_background_one_channel.in"). > > > > Error in routine init_lda_plus_u (1): > > lda_plus_u calculation but Hubbard_l not set > > > I presume that you get this problem because there is something wrong in > your input. If you share your input it would be useful to find what is > wrong. > > > Note that by default the second Hubbard channel per atom is of the "s > character". If you want to change it to something else, then you need to > modify the routine "set_hubbard_l_back". The main Hubbard channel is > specified in "set_hubbard_l" (in your case for Gd it is hard-coded and it > is 4f), and the secondary ("background" [1]) Hubbard channel is specified > in "set_hubbard_l_back" (in your case for Gd you need to specify that it > is the d channel, i.e. hubbard_l_back = 2). This modification must be > done for both DFT+U and DFT+U+V machineries. > > > Greetings, > > Iurii > > > [1] Note, the terminology "background" is a bit misleading. It should not > be called like that (in general), because this is just a second Hubbard > channel per atom. It is called "background" for historical reasons: this > secondary (background) channel was originally implemented to do something > else and hence it has such a name. But we want to change this naming, and > only then advertise these features to the QE community. > > -- > Dr. Iurii TIMROV > Postdoctoral Researcher > STI - IMX - THEOS and NCCR - MARVEL > Swiss Federal Institute of Technology Lausanne (EPFL) > CH-1015 Lausanne, Switzerland > +41 21 69 34 881 > http://people.epfl.ch/265334 > ------------------------------ > *From:* users <[email protected]> on behalf of > William Hewett <[email protected]> > *Sent:* Tuesday, August 18, 2020 4:35:59 AM > *To:* [email protected] > *Subject:* [QE-users] On-site Hubbard U for background orbitals > > Hi all, > > I'm interested in doing DFT+U calculations on the rare earth mono-nitride > GdN. The most successful calculations in the past have used multiple > Hubbard U terms (U_f and U_d) on the 4f and 5d electron channels on the Gd > ion. This has been done before using QE (Comput. Mater. Sci 95 (2014) > 263-270). > > I suspect that in v6.6 this may now be possible in the stable branch via > an onsite Hubbard V term on both the standard and background orbitals? > > The pw.x input guide gives that Hubbard_V(na,na,k) will be the onsite > Hubbard interaction. After setting the appropriate values for the > background n, l and occupations of Gd in: > > Modules/set_hubbard_l.f90 > Modules/set_hubbard_n.f90 > PW/src/tabd.f90 > > and increasing sc_size = 3 in Modules/parameters.f90 > > and compiling the code, I've used the following in the &SYSTEM block: > > lda_plus_u=.true. > lda_plus_u_kind=2 > Hubbard_V(1,1,1)=a > Hubbard_V(1,1,3)=b > > I guess there will now be two Hubbard terms on that atom at side na, on > the standard and background orbitals. > > However, I find the following error: > > Error in routine init_lda_plus_u (1): > lda_plus_u calculation but Hubbard_l not set > > Any help is appreciated, I'm running QE 6.6 on Ubuntu 20.04. > > Thanks > > Will Hewett > Postdoctoral Researcher > Victoria University of Wellington > New Zealand > _______________________________________________ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) > users mailing list [email protected] > https://lists.quantum-espresso.org/mailman/listinfo/users
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